Multi-band antenna

Abstract

A multi-band antenna has a first radiating conductor defining a first side connected to a feeding conductor and a short portion, and a second side opposite to the first side and connected to a second radiating conductor, a third radiating conductor and a fourth radiating conductor. The second radiating conductor is arranged between the third radiating conductor and the fourth radiating conductor. The length of the first radiating conductor and the second radiating conductor resonates at a first frequency range and a second frequency range which is double frequency higher than the first frequency range. The length of the first radiating conductor and the third radiating conductor resonates at a third frequency range which is higher than and close to the second frequency range. The dimension of the fourth radiating conductor has an effect on antenna characteristics in the third frequency range.

1. A multi-band antenna, comprising:
 a first radiating conductor defining a first side and a second side opposite to said first side; 
 a feeding conductor connected to said first side of said first radiating conductor; 
 a short conductor arranged close to said feeding conductor and connected to said first side of said first radiating conductor; and 
 a second radiating conductor having a first portion and a second portion, one end of said first portion connecting said second side of said first radiating conductor, the other end of said first portion connecting vicinity of one end of said second portion to form an angle between said first portion and said second portion; 
 a third radiating conductor having a third portion, a fourth portion and a fifth portion, said third portion connecting said second side of said first radiating conductor, said fourth portion connecting said third portion and said fifth portion, said fifth portion arranged between said third portion and said first portion of said second radiating conductor; and 
 a fourth radiating conductor connected to said second side of said first radiating conductor, said second radiating conductor arranged between said third radiating conductor and said fourth radiating conductor. 
 
   
   
     2. The multi-band antenna as claimed in  claim 1 , wherein said second radiating conductor is formed as a L-shape. 
   
   
     3. The multi-band antenna as claimed in  claim 1 , wherein said third radiating conductor is formed as an U-shape. 
   
   
     4. The multi-band antenna as claimed in  claim 1 , wherein said fourth radiating conductor has a sixth portion and a seventh portion, said sixth portion is connected to said second side of said first radiating conductor, said seventh portion is connected to said sixth portion and arranged at the same direction in relation to said first portion of said second radiating conductor. 
   
   
     5. The multi-band antenna as claimed in  claim 4 , wherein said first radiating conductor defines a third side and a fourth side opposite to said third side, the other end of said second portion of said second radiating conductor and an outer side of said third portion of said third radiating conductor are at the same level with said third side of said first radiating conductor. 
   
   
     6. A multi-band antenna, comprising:
 a ground portion; 
 a first radiating conductor defining a first side and a second side opposite to said first side; 
 a feeding conductor connected to said first side of said first radiating conductor; 
 a short conductor arranged close to said feeding conductor and connected to said first side of said first radiating conductor and said ground portion; 
 a second radiating conductor defining two ends, one end of said second radiating conductor connected to said second side of said first radiating conductor, the length of said first radiating conductor and said second radiating conductor resonated at a first frequency range and a second frequency range higher than said first frequency range; 
 a third radiating conductor defining two ends, one end of said third radiating conductor connected to said second side of said first radiating conductor and the other end of said third radiating conductor connected to said ground portion, the length of said first radiating conductor and said third radiating conductor resonated at a third frequency range which is higher than and close to said second frequency range; and 
 a fourth radiating conductor connected to said second side of said first radiating conductor, wherein the dimension of said fourth radiating conductor is tunable for adjusting antenna characteristics in said third frequency range. 
 
   
   
     7. The multi-band antenna as claimed in  claim 6 , wherein said second radiating conductor is arranged between said third radiating conductor and said fourth radiating conductor. 
   
   
     8. The multi-band antenna as claimed in  claim 7 , wherein said first radiating conductor defines a third side and a fourth side opposite to said third side, said feeding conductor is arranged close to said third side of said first radiating conductor. 
   
   
     9. The multi-band antenna as claimed in  claim 8 , wherein said second radiating conductor has a first portion defining opposite ends and a second portion defining opposite ends, one end of said first portion is connected to said first radiating conductor, the other end of said first portion is connected to vicinity of one end of said second portion, the other end of said second portion is at the same level with said third side of said first radiating conductor. 
   
   
     10. The multi-band antenna as claimed in  claim 9 , wherein said third radiating conductor has a third portion connected to said first radiating conductor and defining a first outer side at the same level with said third side of said first radiating conductor, a fourth portion connected to said third portion and defining a second outer side facing said second portion of said second radiating conductor, and a fifth portion connected to said fourth portion and said ground portion and arranged between said first portion of said second radiating conductor and said third portion. 
   
   
     11. The multi-band antenna as claimed in  claim 10 , wherein said fourth radiating conductor has a sixth portion and a seventh portion, said sixth portion is connected to the corner of said first radiating conductor which is formed by said second side and said fourth side of said first radiating conductor, said seventh portion is connected to said sixth portion and arranged at the same direction in relation to said first portion of said second radiating conductor.